<template>
  <view>
    <view class="search-box">
       <my-search @click="gotoSearch"></my-search>
    </view>
   
    <view class="scroll-view-container">
       <scroll-view class="left-scroll-view" scroll-y  :style="{height: wh + 'px'}" :scroll-top="scrollTop">
          <view :class="['left-scroll-view-item', i === active ? 'active' : '']"   v-for="(item, i) in cateList" @click="activeChanged(i)">
            {{item.cat_name}}
          </view>
       </scroll-view>
       
       <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}">
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
            <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
             <!-- 动态渲染三级分类的列表数据 -->
                <view class="cate-lv3-list">
                  <!-- 三级分类 Item 项 -->
                  <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                    <!-- 图片 -->
                    <image :src="item3.cat_icon"></image>
                    <!-- 文本 -->
                    <text>{{item3.cat_name}}</text>
                  </view>
                </view>
          </view>
       </scroll-view>
  
    </view>
  </view>
</template>

<script>
  // 导入自己封装的 mixin 模块
  import badgeMix from '@/mixins/tabbar-badge.js'
  
  export default {
    // 将 badgeMix 混入到当前的页面中进行使用
    mixins: [badgeMix],
    // 省略其它代码...
    data() {
      return {
        wh: 0,
         cateList: [],
         active: 0,
         cateLevel2: [],
         scrollTop: 0 
      };
    },
    onLoad() {
          // 获取当前系统的信息
          const sysInfo = uni.getSystemInfoSync()
          // 为 wh 窗口可用高度动态赋值
          this.wh = sysInfo.windowHeight - 50
          this.getCateList()
        },
        methods: {
          async getCateList() {
          try{
            // 发起请求
            const { data: res } = await uni.$http.get('/api/public/v1/categories')
            this.cateList = res.message
            this.cateLevel2 = res.message[0].children
          }catch(err){
            uni.$showMsg()
          }
          },
          activeChanged(index){
            this.active = index
            this.cateLevel2 = this.cateList[index].children
             this.scrollTop = this.scrollTop === 0 ? 1 : 0
          },
          // 点击三级分类项跳转到商品列表页面
          gotoGoodsList(item3) {
            uni.navigateTo({
              url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
            })
          },
            // 跳转到分包中的搜索页面
             gotoSearch() {
               
               uni.navigateTo({
                 url: '/subpkg/search/search'
               })
             }
        }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
.search-box {
  // 设置定位效果为“吸顶”
  position: sticky;
  // 吸顶的“位置”
  top: 0;
  // 提高层级，防止被轮播图覆盖
  z-index: 999;
}
</style>
